God does not promise that He will improve our nature, or that He will
mend our broken hearts. No; the promise is, that He will give us new
hearts and right spirits. Human nature is too far gone ever to be
mended. It is not a house which is a little out of repair, with here and
there a slate blown from the roof, and here and there a piece of plaster
broken down from the ceiling. No; it is rotten throughout; the very
foundations have been sapped; there is not a single timber in it which
is sound; it is all rottenness from its uppermost roof to its lowest
foundation, and ready to fall. God doth not attempt to mend; He does not
shore up the walls, and re-paint the door; He does not garnish and
beautify, but He determines that the old house shall be entirely swept
away, and that He will build a new one. It is too far gone to be mended.
If it were only a little out of repair, it might be restored. If only a
wheel or two of that great thing called “Manhood” were out of repair,
then He who made man might put the whole to rights; He might put a new cog where it had been broken off, and another wheel where it had gone to
ruin, and the machine might work anew. But no; the whole of it is out of
repair; there is not one lever which is not broken; not one axle which
is not disturbed. “The whole head is sick, and the whole heart is faint.
From the sole of the foot to the crown of the head, it is wounds, and
bruises, and putrefying sores.” The Lord, therefore, does not attempt
the repairing of this thing, but He says, “A new heart also will I give
you, and a new spirit will I put within you.”